Wireless terminal with reduced SAR peak value and method for reducing SAR peak value by using the wireless terminal

Abstract

A wireless terminal with a reduced Specific Absorption Rate (SAR) peak value and a method for reducing an SAR peak value by using the wireless terminal are disclosed. The wireless terminal with a reduced SAR peak value includes a first antenna configured to receive or transmit a communication signal, and further includes: a second antenna configured to feed a coupling signal when the first antenna receives or transmits the communication signal, and a signal processing module configured to process the coupling signal to reduce an SAR peak value of the communication signal for a human body. The energy of a superposed signal in a human body orientation is reduced by superposing the coupling signal with the communication signal, so as to reduce the SAR peak value effectively.

The invention claimed is: 
     
       1. A wireless terminal with a reduced Specific Absorption Rate (SAR) peak value, which comprises a first antenna configured to receive or transmit a communication signal, wherein the wireless terminal further comprises:
 a second antenna, configured to feed a coupling signal when the first antenna receives or transmits the communication signal; and 
 a signal processing module, configured to process the coupling signal to reduce an SAR peak value of the communication signal for a human body; and 
 a human body sensor, configured to sense and output orientation information of the human body; 
 wherein the signal processing module is further configured to: 
 receive the orientation information of the human body, 
 determine, according to the orientation information of the human body and an amplitude and a phase of the communication signal, the amplitude and the phase of the coupling signal corresponding to a minimum value of the energy of the near-field superposed signal in the human body orientation, and 
 adjust the coupling signal according to the determined amplitude and phase of the coupling signal. 
 
     
     
       2. The wireless terminal with a reduced SAR peak value according to  claim 1 , wherein the signal processing module is further configured to:
 adjust an amplitude and a phase of the coupling signal, so as to change an amplitude ratio and a phase difference between the coupling signal and the communication signal and to reduce energy of a near-field superposed signal of the coupling signal and the communication signal. 
 
     
     
       3. The wireless terminal with a reduced SAR peak value according to  claim 2 , wherein the second antenna comprises:
 a second feed source, configured to feed the coupling signal; and 
 a second radiator, configured to receive or transmit the coupling signal. 
 
     
     
       4. The wireless terminal with a reduced SAR peak value according to  claim 3 , wherein the second radiator is a tortuous conducting line or a conducting strip with multiple branches. 
     
     
       5. The wireless terminal with a reduced SAR peak value according to  claim 4 , wherein the human body sensor is an optical sensor, a thermal sensor, a gravity sensor or a proximity sensor, and the human body sensor includes multiple human body sensors distributed on each inner surface of the wireless terminal. 
     
     
       6. The wireless terminal with a reduced SAR peak value according to  claim 1 , wherein the second antenna is further configured to feed the communication signal, and receive or transmit the communication signal. 
     
     
       7. A method for reducing a Specific Absorption Rate (SAR) peak value by using a wireless terminal, comprising:
 feeding a coupling signal when a communication signal is received or transmitted; and 
 processing the coupling signal to reduce an SAR peak value of the communication signal for a human body; 
 wherein the step of processing the coupling signal to reduce an SAR peak value of the communication signal for a human body comprises: 
 adjusting an amplitude and a phase of the coupling signal, so as to change an amplitude ratio and a phase difference between the coupling signal and the communication signal and to reduce energy of a near-field superposed signal of the coupling signal and the communication signal; and 
 the method further comprises: before the amplitude and the phase of the coupling signal are adjusted, 
 sensing orientation information of the human body; and 
 determining, according to the orientation information of the human body and an amplitude and a phase of the communication signal, the amplitude and the phase of the coupling signal corresponding to a minimum value of the energy of the near-field superposed signal in the human body orientation.